<template>
  <view class="u-swiper-indicator">
    <view
        v-if="indicatorMode === 'line'"
        :class="[`u-swiper-indicator__wrapper--${indicatorMode}`]"
        :style="{
				width: $u.addUnit(lineWidth * length),
				backgroundColor: indicatorInactiveColor
			}"
        class="u-swiper-indicator__wrapper"
    >
      <view
          :style="[lineStyle]"
          class="u-swiper-indicator__wrapper--line__bar"
      ></view>
    </view>
    <view
        v-if="indicatorMode === 'dot'"
        class="u-swiper-indicator__wrapper"
    >
      <view
          v-for="(item, index) in length"
          :key="index"
          :class="[index === current && 'u-swiper-indicator__wrapper__dot--active']"
          :style="[dotStyle(index)]"
          class="u-swiper-indicator__wrapper__dot"
      >

      </view>
    </view>
  </view>
</template>

<script>
import props from './props.js';

/**
 * SwiperIndicator 轮播图指示器
 * @description 该组件一般用于导航轮播，广告展示等场景,可开箱即用，
 * @tutorial https://www.uviewui.com/components/swiper.html
 * @property {String | Number}  length          轮播的长度（默认 0 ）
 * @property {String | Number}  current          当前处于活动状态的轮播的索引（默认 0 ）
 * @property {String}      indicatorActiveColor  指示器非激活颜色
 * @property {String}      indicatorInactiveColor  指示器的激活颜色
 * @property {String}      indicatorMode      指示器模式（默认 'line' ）
 * @example  <u-swiper :list="list4" indicator keyName="url" :autoplay="false"></u-swiper>
 */
export default {
  name: 'u-swiper-indicator',
  mixins: [uni.$u.mpMixin, uni.$u.mixin, props],
  data() {
    return {
      lineWidth: 22
    }
  },
  computed: {
    // 指示器为线型的样式
    lineStyle() {
      let style = {}
      style.width = uni.$u.addUnit(this.lineWidth)
      style.transform = `translateX(${uni.$u.addUnit(this.current * this.lineWidth)})`
      style.backgroundColor = this.indicatorActiveColor
      return style
    },
    // 指示器为点型的样式
    dotStyle() {
      return index => {
        let style = {}
        style.backgroundColor = index === this.current ? this.indicatorActiveColor : this.indicatorInactiveColor
        return style
      }
    }
  },
}
</script>

<style lang="scss" scoped>
@import "../../libs/css/components.scss";

.u-swiper-indicator {

  &__wrapper {
    @include flex;

    &--line {
      border-radius: 100px;
      height: 4px;

      &__bar {
        width: 22px;
        height: 4px;
        border-radius: 100px;
        background-color: #FFFFFF;
        transition: transform 0.3s;
      }
    }

    &__dot {
      width: 5px;
      height: 5px;
      border-radius: 100px;
      margin: 0 4px;

      &--active {
        width: 12px;
      }
    }

  }
}
</style>
